Improvement in elevators



M. L. WY MAN Elevators.

N0.\52,7\8.. Patentedlune30,1874.

I rcxear 7 wgv UNITED STATES PATENT OFFICE.

MART[N L. 'WYMAN, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO HIMSELF AND CHARLES E. MOORE, OF SAME LACE.

IMPROVEMENT IN ELEVATORS.

Specification forming part of Letters Patent No. 152,7l8, dated June 30, 1874; application filed February '7, 1874.

To all whom it may concern:

Be it known that I, MARTIN L. WYMAN, of Boston, in the county of Suffolk and State of Massachusetts, have invented an Improvement in Elevators; and I do hereby declare that the following, taken in connection with the drawings which accompany and form part of this specification, is a description of my invention suflicient to enable those skilled in the art to practice it.

The invention has reference to a novel construction of a fluidretarder mechanism to be used in connection with hotel and warehouse elevators, to regulate the descent of the car.

In my invention I place at one end of the drum shaft a liquid containing chamber, the drum-shaft passing through the wall of the chamber, and having upon its end within the chamber a gear that meshes into and drives a gear journaled in the chamber-walls. Extending around, or partially around, the second gear is a partition, separating the gearehamber from another chamber or channel communicating, at each end, with the main chamber, but having at one end avalve, which, resting upon its seat, covers the channel, and, when raised from its seat, leaves a free. passage between the channel and chamber, said valve having a small orifice extending through it, so that when closed there is a restricted passage between the channel and chamber.

In the rotation of the drum and drum-gear, as the car is raised the two gears are so rotated as to impel the liquid through the channel from the open end toward the valve controlled end thereof, the pressure of the water opening the valve, and the liquid circulating freely from chamber to channel, and channel to chamber. The weight of the valve holds it normally upon its seat, to cover the channelmouth; and, as the drum and gear rotate in the opposite direction as the car descends, the rotation of the gears forces the liquid against the closed valve, and, as the liquid can only enter the channel through the valve-orifice, the resistance offered by the liquid to the rotation of the gears insures the slow descent of the car, or its descent as fast, and only as fast, as the liquid can pass through the valveaperture into the channel.

The invention consists in the combination, with the hoisting drum, of a retarding mechanism, acting as thus generally described.

The drawing represents an elevator and a retarding mechanism embodying my invention.

Figure 1 shows the elevator in plan. Fig. 2 is a side elevation, the cap plate of the retarder mechanism being removed. Fig. 3 is an enlarged elevation, showing the open valve. Fig. 4 isasimilar elevation, showing the closed valve.

(t denotes thehoisting-drum, having its shaft journaled in suitable bearings. b is the car c, the hoistingrope. Upon the end of the shaft (1 is fixed a gear, 0, meshing into a gear, f, the journals of which gear f are supported in suit able bearings in. the side walls 1 of a case, 74. The two gears are contained within the chamber i of this case, the gears occupying the main part of the chamber, and there being, in the lower part of the chamber, a channel, is, separated from the gear f by a partition, I, which partition is concentric with, and close to, the teeth of said gear, as seen in Figs. 2 and 3. The channel opens into the main chamber at one end, as seen at m, and its opposite end opens into the chamber, except as controlled by a valve, a, one end of the partition I, and a shoulder, 0, forming the seat of this valve, the valve normally covering the channel-opening p, as seen in Fig. 2. This valve has an orifice, q, extending through it, so that, when closed, there is still a passage from the chamber to the channelmouth 12, such passage being through this restricted opening (1.

The chamber '0' is filled with oil or other suitable liquid, and when the car is ascending the gears rotate. as denoted by the arrows in Fig. 2, and by their action force the liquid through the channel It in the direction of the arrow seen in Fig. 3, the pressure of the liquid opening the valve, and the liquid circulating freely through the channel and chamber, from chamber to channel and channel to chamber. But,when the drum rotates in the opposite direction, as the car descends, the gears rotate .in the direction of the arrows seen in Fig. 2, and the valve, closed by gravity, obstructs the free passage of the liquid into the channel, the liquid havingto passinto the channel through the orifice q,and the pent-up liquid form in g such impedimentto thefreefiow 0f the liquid into the channel as toinsure theregular descent of the car,and prer'ent, under any and all circumstances, an over-rapid descent of the car. In these operations the teeth of the gearsare the impelling agents to create the flow of the liquid, their meshing-surfaces forming, at all times, a wall against the passage of the water in a direction opposite to their path of rotation.

The chamber and channel may be formed otherwise than in the specific arrangement shown; but the construction represented is simple and eflieient.

I claim- The gear and liquid containing chamber 17, channel 7;, valve 02', and its orifice q, and the gears c f, in combination with the hoistingdrum, and forming a retarder substantially as described.

Executed this 22d (lay of December, A. l). 1J3.

MARTIN L. WYMAN.

\Yitnesses:

0. WA REN BROWN, M. W. FROTHINGIIAM. 

